#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

int main()
{
    pid_t id = fork();
    if(id == 0)
    {
        int cnt = 5;
        while(cnt)
        {
            printf("I am child, pid: %d, ppid: %d, cnt: %d\n", getpid(), getppid(), cnt);
            cnt--;
            sleep(1);
        }
        exit(0);
    }
    else if(id > 0)
    {
        while(1)
        {
            printf("I am father, pid: %d, ppid: %d\n", getpid(), getppid());
            sleep(1);
        }
    }
    else
    {
        printf("fork fail\n");
    }
    return 0;
}
